1. Field of the Invention
The field of the present invention relates generally to devices and procedures for use in endoscopic examinations of the human colon. More specifically, the device and method of the present invention relates to medical equipment and procedures used to overcome the difficulties encountered with looping of the sigmoid during a colonoscopy. Even more specifically, this invention relates to guiding devices and methods of their use which facilitate the insertion of the endoscope into and through the human colon by tilting the endoscope to prevent or overcome problems with sigmoid looping.
2. Background
As used herein, the term “endoscope” or “scope” is used to refer to a endoscope, colonoscope, sigmoidoscope, proctoscope or other types of medical endoscopes. As known to those skilled in the art, a typical endoscope generally comprises a connecting tube, a handle and an insertion tube (the part inserted into the patient). In the text, the term “scope” generally refers to the insertion tube portion of the endoscope. In referring to the opposite ends of the scope or the guide of the present invention, the “proximal end” refers to that part of the scope or guide which is closest to the operator or physician endoscopist (hereinafter collectively referred to as “operator”) performing the procedure, and the “distal end” refers to that part of the scope or guide farthest from the operator or physician endoscopist. Although medically the rectum is generally not considered to be part of the colon, which includes the sigmoid colon, descending colon, transverse colon and ascending colon, for purposes of this disclosure general references herein to the term “colon” include the rectum. The terms “splint”, “splinting device”, and “overtube” are used interchangeably to refer to a generally elongated hollow tubular member that is adaptable for receiving a medical instrument, such as an endoscope, therein to facilitate movement of the scope through the colon.
Colonoscopy is the most sensitive and specific means for examining the colon, particularly for the diagnosis of colon cancers and polyps. Because the cecum, the portion of the colon farthest from the anus, can be a common location for cancer, it is generally desirable that the entire colon be completely examined. During a typical colonoscopy procedure, the scope is inserted into the anus, through the rectum, and then advanced through the sigmoid colon, descending colon, transverse colon, ascending colon and into the cecum. In colonoscopy, straightness of the endoscope is necessary, or at least highly desirable, for the advancement of the endoscope through the colon. Advancing the scope, which is typically about 160 centimeters in length, can be difficult due to a loop in the sigmoid colon. In fact, the advancement of the scope during the colonoscopy procedure often results in the formation of a loop along the shaft of the flexible scope. This looping occurs most commonly in the sigmoid colon and, though usually much less frequently, in the transverse colon. As known to those skilled in the art, failure to substantially straighten the loop in the sigmoid colon prior to continuing to advance the scope can cause enlargement of the loop and result in even more difficulty in advancing the scope. This enlarged looping can result in patient pain and damage, including cardiovascular reactions such as hypotension and bradycardia. Forceful pushing of the scope in the colon when loops are present only increases the pain and is usually ineffective in advancing the scope through the colon. Pain increases the need for sedative and analgesic medications, which can expose the patient to more cardiorespiratory risk.
To address the issue of looping in a colonoscopy, the operator typically utilizes a series of maneuvers, referred to herein as the usual colonoscopic maneuvers, that can be summarized as pushing, pulling, rotating (clockwise or counterclockwise), jiggling, inflation, deflation (suction), external abdominal compression and changing the patient's position, which are done in various combinations and/or sequences as necessary or desirable. The scope is inserted into the rectum and gradually advanced with the usual colonoscopic maneuvers through the sigmoid. In a typical colonoscopy, the sigmoid loop is formed as the scope moves inward. The operator will reduce and then straighten the sigmoid loop by withdrawing the scope to a generally straightened position after he or she reaches the descending colon or the transverse colon. Once the loop is substantially straightened, further advancement of the endoscope can usually be accomplished. Unfortunately, it is not uncommon that upon readvancement of the scope, the sigmoid loop has a tendency to reform. The operator will attempt to prevent or limit reformation of the sigmoid loop with abdominal compression and by changing the position of the patient, thereby allowing advancement of the scope to the cecum. As well known, however, the usual colonoscopic maneuvers are ineffective in a certain number of cases. In fact, subsequent reformation of the sigmoid loop is the most troublesome impediment to the advancement of the distal tip of the scope and accounts for many, if not most, of the failures to reach the cecum, which typically results in three to ten percent of colonoscopies.
The variable stiffness colonoscopes, such as the Innoflex™ video colonoscope available from Olympus America, Inc., is somewhat helpful in dealing with the problem of sigmoid looping during colonoscopy. The use of a sigmoid splint or overtube has also been found to be highly effective in preventing reformation of the sigmoid loop in order to facilitate advancement of the scope through the colon during a colonoscopy. The prior art sigmoid splinting overtubes are all inserted over a straightened scope through the rectum and sigmoid into the descending colon to passively form a bridge between the anus and the descending colon so as to facilitate further scope advancement. These overtubes are all fairly flexible in order to be safely inserted into the descending colon and none of them are of graduated rigidity. As such, the prior art overtubes are not capable of actively tilting the axis of the scope in the rectum, which is the objective of the present invention. Furthermore, the method of using a short overtube, sufficiently rigid, to actively tilt a flexible endoscope in the rectum, has never been disclosed.
As is well known, splints are not easy to use and can cause complications such as perforation. In addition, when the need for a sigmoid splint arises, the tip of the scope is usually already in the proximal colon. At this point, the operator may opt to remove the scope entirely in order to load the endoscope inside the sigmoid splint, in an end-to-end fashion, and start the procedure over again. A more convenient way, however, is to be able to load the endoscope into the splint without having to remove the scope from the patient. This is done by using a splint with a longitudinal slot along the length of the splint. The slotted splint is loaded onto the endoscope in a side-to-side fashion by opening the slot, such that the scope does not have to be removed from the patient. Once placed around the scope, the slot is closed. The slot will then need to be fastened or locked in the closed position. A fastening or locking mechanism is needed to keep the splint closed in a secure fashion. There are many patents that teach the use of overtubes/splints for colonoscopy, including U.S. Pat. No. 5,779,624, U.S. Pat. No. 5,941,815 and U.S. Pat. No. 6,712,755, all to Chang (the present inventor).
In addition to variable stiffness scopes and the use of splints, the old-fashioned rigid proctoscope/sigmoidoscope has existed for decades. These rigid scopes are used for the purpose of examining the rectum and part of the sigmoid. When in the rectum, they have to be angled in various directions, often quite severely, to gain optimal views. The fact that these devices have been in use for many years shows that tilting a round, cylinder-shaped instrument in the rectum is safe. However, these rigid proctoscopes/sigmoidoscopes directly tilt the rectum. They do not tilt flexible endoscopes and have never been designed or designated for facilitating the advancement of a flexible endoscope through the colon.
A video proctoscope is described in “Practical Gastrointestinal Endoscopy”, by Peter Cotton and Christopher Williams, 4th edition, p. 219. A proctoscope is first inserted into the distal rectum. The insertion trocar is removed. A flexible colonoscope is next inserted into the proctoscope. The colonoscope provides a source of illumination and an excellent close-up view of the distal rectum and anus, especially of hemorrhoids. This combination is used to gain a good view of the distal rectum, but not to facilitate colonoscopy. Specifically, no mention is made in this text of using the proctoscope to tilt the path of the colonoscope. Furthermore, the short proctoscope shown in the illustration (FIG. 9.22) is insufficient in length to tilt the colonoscope at or near the rectum-sigmoid junction in order to facilitate colonoscopy.
Despite the prevalence of specially configured endoscopes and splints to reduce sigmoid looping in order to improve the effectiveness and reduce the pain of colonoscopy procedures, many operators still face significant difficulty and, on occasion, are unable to reach the cecum due to looping of the sigmoid. As a result, therefore, what is needed is a device and a method of using that device that improves the use of an endoscope during a colonoscopy by reducing the problems associated with insertion and advancement of the scope through the colon. The improved device and method should simplify the colonoscopy procedure and reduce the operator labor and patient discomfort presently associated with colonoscopies that result from sigmoid looping. Preferably, the device should be relatively inexpensive to manufacture, easy to use and adaptable for use at various stages of the colonoscopy.